Abstract:Objective：The Neoarchean intrusions in Urad zhongqi (Central Urad Banner) area，Inner Mongolia，possesses obvious characteritics of Adakite （high Sr low Yb intermediate—acid rocks）and TTG rock series. It is associated intently with greenstone of Seertengshan Group Neoarchean in space distribution. It possesses important signifcance in studying the early Earth evolution of the Norh China Craton.Methods:This articale did the study to the Neoarchean granites via SHRIMP ziron U-Pb dating and whole rock geochemistry analysis collected from the Urad Zhongqi Region, Inner Mongolia.Results: The SiO2 content of these intrusive rocks is in the range of 58.24%~71.19%， with a high alkali content (Na2O+K2O＞7%)，enriched in Na(Na2O ＞3.82%)， Na2O/K2O＞1， high alumina(Al2O3 content usually between 13.89%~16.92%).Trace elements show low Rb/Sr ratio (0.06＜Rb/Sr＜0.28)， enriched in LILE(Rb、Sr) and depleted in HFSE(Th、Nb、Ta) . The SHRIMP was used for the zircon U Pb dating of the intrusive rocks， and the isotope age is 2616±24Ma and 2577±19Ma， indicating that it was formed at the Late Neoarchaean and representing the hydrothermal age. By the edge of zircon testing，obtained isotope is 2504±15Ma and 2486±26Ma respectively. between with the Late Neoarchaean to Early Paleoproterozoic， Representing the metamorphic age. The Neoarchaean intrusions in this area enriched in Sr， low Rb/Sr value， the average Mg# value is 0.53. And result is lower compared with Mg# (0.65～0.80)of adakite formed by slab subduction melting，shows the TTG of this area was formed by partial melting of the thickened crust.Conclusions: Combined with regional geological data and the zircon U Pb ages，the Neoarchean magmatic activity of Urad zhongqi area is widespread in the whole North China Craton(NNC) and its corresponding metamorphic event is also widely distributed in area， revealing that both the magmatism and metamorphism were derived from the same tectonic thermal geodynamic precesses. And therefore，we suggested that the Neoarchean magmatism was caused by the mantle magma underplating to the lower crust，which was most likely to be derived from the mantle plume activity， and the widely magmatic event may be associated with the formation mechanism of the NNC.